package cn.tedu.v6;
import java.io.*;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;

public class Server {
     private static final Integer PORT =7878;
     private ServerSocket serverSocket;
     private List<PrintWriter> allOut=new ArrayList<>();
     //1.私有集合，保存所有用户名
     private Set<String> onlineUsers=new HashSet<>();
     private Map<String, String> userDatabase;

     public Server() {
        try {
            serverSocket = new ServerSocket(PORT);
            //2.Server对象启动--main方法--创建服务器之初，完成对账号和密码的赋值
             userDatabase=new HashMap<>();
             userDatabase.put("李佳怡","123456");
             userDatabase.put("李总","654321");
        } catch (BindException e) {
            System.out.println("端口号重复申请，建议换个端口号");
        } catch (IOException e) {
            System.out.println("申请端口号失败");
        }
    }
    public static void main(String[] args) {
        new Server().start();
    }
    public void start() {
         try {
             while (true) {
                 System.out.println("------ 等待客户端链接 ------");
                 Socket socket = serverSocket.accept();

                 String ip = socket.getInetAddress().getHostAddress();
                new Thread(new ClientHandler(socket)).start();
            }

        } catch (IOException e) {
            System.out.println("与服务器断开链接了");
        } finally {
            if (serverSocket != null && !serverSocket.isClosed()) {
                try {

                    serverSocket.close();
                } catch (IOException e) {
                    System.out.println("服务器关闭失败");
                }
            }
        }
    }

    private synchronized void broadcastMessage(String message){
        for(PrintWriter pw:allOut){
        pw.println("消息广播"+message);
        }
    }
     //封装方法：同步转发给所有客户端消息 方法名叫onlineUsers “在线用户”+onlineUsers
     //updateOnlineUsers更新在线人数的方法：“在线用户：”+onlineUsers
     //字符串：String userList=“在线用户”+String.join("、",onlineUsers)
    private synchronized void updateOnlineUsers() {
       String userList="在线用户:"+String.join("、",onlineUsers);
         for(PrintWriter pw:allOut){
          pw.println(userList);
      }
    }
    private class ClientHandler implements Runnable {
        private Socket socket;
        private String ip;
        private BufferedReader br;
        private PrintWriter pw;
        private String username;
        private String password;

     public ClientHandler(Socket s) {
        this.socket = s;
        ip = socket.getInetAddress().getHostAddress();
        try {
           br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF8"));
           pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF8")), true);
             synchronized (allOut) {

                    allOut.add(pw);

                }
            } catch (IOException e) {
           System.out.println("客户端断开通讯");
          }
        }
        private boolean Login(String user,String pass){
         return userDatabase.containsKey(user)&&userDatabase.get(user).equals(pass);
        }
        private void handleChat(){
            new Thread(() -> {
               try {
               String message;
               String On;
               while ((message = br.readLine()) != null) {
                  System.out.println("客户端说：" + message);
                  System.out.println("请服务器端输入：");
                  broadcastMessage(message);
                  if (br.readLine().equalsIgnoreCase("exit")) {
                                        //关闭
                            break;
                        }
     }
                } catch (IOException e) {
                 System.out.println("服务器端读入失败");
                 }
             }).start();
              Scanner input = new Scanner(System.in);
              while (true) {

                  System.out.println("请服务器端输入：");
                 String say = input.nextLine();

                 pw.println("服务器说：" + say);
                 if (say.equalsIgnoreCase("exit")) {  //关读
                       System.out.println(username+"客户端断开连接IP是："+ip);
                    pw.println(username+"退出聊天室");
                    Close();
                    break;
                }
            }
        }
        public void run() {
             try {
             pw.println("请输入用户名:");
             username = br.readLine();
             pw.println("请输入密码:");
             password = br.readLine();
             if(Login(username,password)){
             pw.println("登录成功，欢迎进入聊天室");
             //3.把所有用户添加至集合中
             synchronized (onlineUsers){
             onlineUsers.add(username);
                    }
            updateOnlineUsers(); // 更新在线用户列表
             System.out.println("李总" + ip + "连接成功了");
             pw.println("请输入消息(输入 exit 退出)：");
              handleChat();
                }else {//不通过的情况
             pw.println("登录失败，用户名或者密码错了");
             socket.close();//登录失败，关闭连接
                }
            } catch (NullPointerException e) {
                System.out.println("IO流传入对象，有对象为空，立马核对，建议查看try块中对象可能赋值为null");
            } catch (IOException e) {
                System.out.println("服务器端断开连接");
            } finally {
            Close();
            //4.客户端断开链接，移除当前集合【同步】
           synchronized (allOut) {
          // 4.客户端断开链接，移除当前集合【同步】
           onlineUsers.remove(username);
            }
          updateOnlineUsers(); // 更新在线用户列表
          synchronized (allOut) {
          allOut.remove(pw); // 从输出流列表中移除当前客户端的输出流

                }
            }

        }
        //封装一个针对关闭的功能：Close()
        private void Close(){
         synchronized (allOut) {
           allOut.remove(pw);
            }
            if (br != null)
                try {
                    br.close();
                } catch (IOException e) {
                    System.out.println("结束通讯：关闭失败");
                }
            if(pw!=null) pw.close();
            if(socket!=null&&!socket.isClosed())
                try {
                    socket.close();
                } catch (IOException e) {
                    System.out.println("通讯关闭失败");
                }
        }

    }
}
